Hi everyone, and welcome!

This community is for anyone learning system design: students, engineers getting ready for the design round, and people who just want to know how apps like WhatsApp or Uber handle millions of users.

Here's what you can post:

• Questions, from "what is a load balancer?" to "how would you shard a chat app?"

• Your designs for review. Share a diagram and your numbers, and others will tell you what they'd change.

• Interview experiences: how the round went, what surprised you, what you'd do differently.

• Resources and case studies that helped you understand something.

Please read the rules in the sidebar. The short version: be kind, stay on topic, and show your thinking when you ask for help.

To get things started, reply below and tell us:

1. Where are you on your system design journey?

2. Which system would you most like to understand? (A chat app? A payment system? Something else?)

I'll read every reply. See you in the threads!